What we need to know now is where your information came from.  As Bruce mentioned earlier in this thread, the earliest known printed version of this song is of 1881; Barney, to which it is clearly related, being apparently earlier.  It would appear that no author has ever been identified for either song, and there is no evidence that My Bonnie is in any way Scottish.  At this stage I see no reason to think that it was not an American composition, perhaps based on a vaudeville "Stage Irish" Barney.

I would certainly be very interested to see any verifiable information about its origins, as I'm sure would a great many people; it's not an interesting song textually or musically, but it's so widely known that we really ought to know more about it.  The trouble is that so many people simply accept uncritically the myths about it (if it's a Jacobite song, for example, then I'm Atilla the Hun) and repeat hearsay as fact.

Toadfrog has now posted a set of lyrics for My Barney in the more recent thread:  BARNEY

It may be helpful to look at them for purposes of comparison, though of course there is no guarantee that they have not at some point been mixed with the better-known song.